JP2013127311A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint that facilitates determining whether normal processing is performed by measuring and inspecting electrical conductivity between a pipe and a joint.SOLUTION: A pipe joint includes a pipe joint body, a sleeve 2 for holding a pipe end, and a nut screwed into a screw of the joint body. The sleeve 2 comprises: a plurality of metal segments 22 having claws 23 protruding toward a radial inside diameter side at their one-side ends, and abutting parts 26b which abut on push-press faces formed at the nut when the screw-in of the nut to the joint body is completed at their other ends; and a ring-shaped synthetic resin base body 21 formed by integrally molding these metal segments. On the synthetic resin base body, there is formed a step 27a which protrudes toward the nut from the abutting parts of the metal segments, and abuts on the push-press face formed at the nut.

Description

  The present invention relates to a pipe joint connected to a pipe for flowing a fluid, and more particularly to a pipe joint having improved electrical continuity with the pipe.

  Conventionally, a flexible metal corrugated pipe has been used as a pipe for supplying gas and water. As a pipe joint to be connected to this type of corrugated pipe, Patent Document 1 discloses a joint comprising a joint body, a sleeve for holding the end of the corrugated pipe in the through hole, and a nut screwed into a screw of the joint body. The joint body has a shoulder portion with an airtight surface inside, and an inner surface of the through hole that is adjacent to the shoulder portion and one end of the sleeve is fitted, and an annular recess that is adjacent to the inner surface. Grooves are formed, and the sleeve protrudes radially inward from the end facing the joint body shoulder, and the sleeve has an end face at the other end, and the protrusion is elastic from other parts. The nut has a pivotal motion and enters the trough of the corrugated tube, and the nut has means for holding the outer surface of the sleeve projection in a location facing the annular groove of the joint body and a flange surface that presses against the end surface of the sleeve. Korge Invention DOO Pipe Fittings have been disclosed.

  A gasket is attached to the shoulder portion of the joint body, and by tightening a nut, the end portion of the corrugated pipe is pressed against the gasket to be hermetically sealed and connected. The sleeve also has a plurality of metal segments each having a projecting portion projecting toward the radially inner diameter side and having a contact surface at the other end contacting the pressing surface formed on the nut, and the metal segments. It is composed of a composite member with a ring-shaped synthetic resin substrate integrally molded.

  On the other hand, in European standard EN15266 (a stainless steel corrugated flexible pipe system for indoor piping gas with a working pressure of 0.5 bar or less), a corrugated pipe of a predetermined length and a pipe joint are connected to both ends of the test piece. When a voltage of 12 V is applied, the electrical resistance value between both ends is determined to be 0.25Ω or less. This is to prevent a spark from being generated between the pipe and the pipe joint when an induced current caused by a lightning strike or a ground current by a nearby electric welding operation flows through the corrugated pipe.

  As a pipe joint having electrical continuity with a pipe, Patent Document 2 includes a joint body having conductivity, and a conductive means interposed between the metal pipe and the joint body. An invention of a joint structure constituted by electrically connecting through at least one of an O-ring, a bush, a combination of an axial spring and a pad, a combination of a radial spring and a steel ball, or a snap ring is disclosed. Yes.

  Patent Document 3 discloses a pipe joint used for connecting a pipe having a conductive layer on the outer peripheral surface, and has a joint part having an inner hole into which an end of the pipe is inserted, and an inner hole. An invention of a pipe joint provided with a conductor which is provided so as to surround the outer periphery of the pipe inserted into the pipe and conducts between the conductive layer of the pipe and the joint portion is disclosed.

Japanese Patent Laid-Open No. 7-151279 Japanese Patent Laid-Open No. 11-280580 JP 2008-256108 A

  However, the pipe joints described in Patent Documents 1 to 3 have difficulty in determining whether or not normal construction has been performed.

That is, although the pipe joint described in Patent Document 1 is not directly described, the sleeve has a plurality of metal segments having a contact surface at the other end that contacts the pressing surface formed on the nut. When the connection is completed, the projection of the sleeve comes into contact with the pipe, and the contact surface comes into contact with the nut, so that the continuity between the pipe and the joint is ensured in this portion.
However, the determination as to whether or not the normal construction has been performed cannot but depend on the sound and vibration associated with the pivot movement when the corrugated tube is inserted, and the construction operator's sense of screwing the nut into the joint body.

  In the device described in Patent Document 2, when a pipe is inserted into a joint, the pipe and the joint are electrically connected through various forms of conductive means. However, when inserting the pipe, the ring bulging wall formed on the outer periphery of the pipe judges the completion of connection based on the sound and vibration when overcoming the protrusion formed in the inner hole of the joint body. I have to rely on the sense of

The thing of patent document 3 inserts a corrugated pipe | tube until the front-end | tip of a corrugated pipe | tube passes the engagement piece of a stopper member, slides a slide member, and engages a retainer member with the trough part of a corrugated pipe | tube. It is. Therefore, the tip of the corrugated tube must rely on the operator's sense of sound and vibration when passing through the engaging piece of the stopper member.
That is, in the techniques described in Patent Documents 1 to 3, there is a problem that the normal connection construction between the pipe and the joint only depends on the skill of the construction worker, and the construction manager cannot perform the construction management by a simple method.
The present invention has been made in view of the above problems, and a pipe that can easily determine whether or not normal construction has been performed by measuring and inspecting electrical continuity between the pipe and the pipe joint. It aims to provide a joint.

  In order to achieve the above object, a pipe joint according to the present invention includes a joint body having a through hole, a sleeve for holding the end of the corrugated pipe inside the through hole, and a nut screwed into a screw of the joint body. The joint body has a shoulder portion having an airtight surface therein, and a tapered inner surface is formed on the inner surface of the through hole so as to be fitted to one end of the sleeve adjacent to the shoulder portion. Is provided with a gasket for sealing the end of the corrugated tube, and the sleeve is electrically connected between the sleeve and the joint body or until the screw is completely screwed into the joint body. The electrical continuity between the corrugated pipe and the joint body is interrupted by interrupting the electrical continuity with the nut, and after the screwing of the nut into the joint body is completed, the sleeve and the joint Characterized by restoring the electrical connection between the joint body and the corrugated tube an electrical conduction between the electrically conductive or the sleeve of the body and the nut by restoring the action of screwing of the nut.

  According to a second aspect of the present invention, there is provided a pipe joint comprising: a joint main body having a through hole; a sleeve for holding an end of the corrugated pipe inside the through hole; and a nut screwed into a screw of the joint main body. Has a shoulder portion having an airtight surface inside, and a tapered inner surface is formed on the inner surface of the through hole so as to be fitted to one end of the sleeve adjacent to the shoulder portion, and the corrugated tube is formed on the shoulder portion. The sleeve has a claw projecting toward the radially inner diameter side at one end, and when the nut has been screwed into the joint body, the sleeve formed on the nut is disposed on the sleeve. A plurality of metal segments having an abutting portion that abuts against the surface at the other end, and a ring-shaped synthetic resin base body integrally molded with the metal segments, the synthetic resin base body facing the nut Less And a step portion that protrudes from the contact portion of the metal segment, contacts a pressing surface formed on the nut, and the sleeve and the joint body are electrically insulated. And

  According to the above configuration, after the corrugated tube is inserted to a predetermined position, when the nut is started to be screwed, the step portion of the synthetic resin base is first brought into contact with the pressing surface of the nut. In this state, the corrugated pipe and the pipe joint are electrically insulated. When the nut is further screwed in, as the stepped portion of the synthetic resin substrate is deformed and the height is lowered, the contact portion of the metal segment protrudes from the stepped portion and is exposed, and the screwing of the nut is completed. Then, the pressing surface formed on the nut comes into contact with the contact portion of the metal segment. Therefore, when the correct construction is completed, the corrugated pipe and the pipe joint are surely brought into an electrically conductive state. What is necessary is just to measure the continuity with a corrugated pipe and a pipe joint whether correct construction was made.

  According to a third aspect of the present invention, there is provided a pipe joint comprising: a joint body having a through hole; a sleeve for holding an end of the corrugated pipe in the through hole; and a nut screwed into a screw of the joint body. The joint body has a shoulder portion having an airtight surface therein, and a tapered inner surface is formed on the inner surface of the through hole so as to be fitted to one end of the sleeve adjacent to the shoulder portion. A gasket for sealing the end of the corrugated tube is disposed, and the sleeve has a plurality of metal segments each having a claw portion protruding toward the radially inner diameter side, and a ring formed by integrally forming the metal segments. The joint body of the sleeve is formed on the tapered surface side of the sleeve to form a protruding portion in which a portion of the synthetic resin substrate protrudes with the metal segment exposed. Between the serial nut is characterized in that it is electrically insulated.

  According to said structure, after inserting a corrugated pipe | tube to a predetermined position, if the nut begins to be screwed in, the protrusion part of the synthetic resin base | substrate in a sleeve will contact | abut to the taper inner surface of a joint main body. In this state, the corrugated pipe and the pipe joint are electrically insulated. Then, when the nut is further screwed in, as the protruding portion of the synthetic resin base is deformed and becomes lower in height, the outer peripheral surface of the metal segment protrudes from the protruding portion and is exposed, and when the screwing of the nut is completed The tapered inner surface of the joint body and the outer peripheral surface of the metal segment abut. Therefore, when the correct construction is completed, the corrugated pipe and the pipe joint are surely brought into an electrically conductive state. What is necessary is just to measure the continuity with a corrugated pipe and a pipe joint whether correct construction was made.

  According to a fourth aspect of the present invention, there is provided a pipe joint including both a step portion in the second aspect of the invention and a protruding portion in the third aspect of the invention as a sleeve.

  In the above invention, a locking portion is provided in the vicinity of the screw of the joint body, and a locking portion is formed in the vicinity of the screw of the nut. The locking part of the main body can be fitted and locked.

  According to the pipe joint according to the present invention, when the nut is incompletely screwed, the corrugated pipe and the pipe joint are in an insulated state, and when the nut is completely screwed in, the metal segment and the nut or the joint body are electrically connected. It becomes conductive. Therefore, if the continuity between the corrugated pipe and the pipe joint is measured and inspected after the construction, it is possible to easily determine whether the normal construction has been performed along with the electrical continuity.

It is a front view showing the partial section of one example of the joint of the present invention, and shows the state where the nut was loosely attached and the flexible corrugated pipe was inserted. It is the elements on larger scale which show the positional relationship of the latching | locking part of the coupling main body and nut in FIG. It is a front view which shows the partial cross section of the state which fastened the nut with the coupling of FIG. It is the elements on larger scale which show the positional relationship of the latching | locking part of the coupling main body and a nut in FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a sleeve used for the coupling of the 1st form of this invention, (a) is a perspective view, (b) is a side view, (c) is a bottom view. It is a sleeve used for the coupling of the 2nd form of this invention, (a) is a perspective view, (b) is a side view, (c) is a bottom view.

  Hereinafter, an example of an embodiment according to the present invention will be described with reference to the drawings as appropriate.

<First form>
As shown in FIGS. 1 and 3, a pipe joint according to the present invention includes a joint body 1 having a through hole 11, a sleeve 2 that holds an end of a corrugated pipe 4 inside the through hole 11, and a joint body 1. The nut 3 is screwed into the female screw 17. The joint body 1 is made of a conductive metal and has a through hole 11 in its axial direction. The inner surface of the through hole 11 is an airtight surface facing one side (left in the drawing), that is, the drawing. Above it has a shoulder 14 with a gasket 12. The inner surface of the through hole 11 is adjacent to the shoulder portion 14 and has an inner tapered surface 15 having a diameter decreasing toward the shoulder portion 14, followed by an annular groove 16, an internal thread 17, and a locking portion 6. There are cutouts 18 for accommodating O-rings 36 at the ends. On the other side of the joint body 1, a male screw 19 for attaching the joint body 1 to another pipe or the like is attached. In this embodiment, since the screw into which the nut 3 is screwed is the female screw 17, the nut 3 side enters into the through hole 11 of the joint body. As a result, the radial dimension of the joint can be suppressed and the size can be reduced.

  As shown in FIG. 2, the engaging portion 6 of the joint body 1 is formed with an inclined surface 61 that expands toward the notch 18 and an engaging surface 62 on the female screw 17. The inner diameter of the locking portion 6 is larger than the valley diameter of the female screw 17.

  A sleeve 2 that accommodates and holds the free end of the flexible corrugated pipe 4 is inserted into the through hole 11 of the joint body 1. As shown in FIG. 5, the sleeve 2 has an integrated ring 21 at the rear, and the front is divided into segments 22 by axial slits. Thus, a claw portion 23 protrudes toward the inside in the radial direction at a portion facing the shoulder portion 14. A circle d formed by the tip of the claw portion 23 is smaller than the diameter of the peak of the corrugated tube to be inserted and larger than the diameter of the valley.

  In FIG. 5, the hatched portion of the broken line is the outer peripheral portion of the claw portion 23 and the segment 22, which is composed of an integral brass plate 26 to increase rigidity, and the claw portion 23 and the outer peripheral portion of the segment 22 are electrically connected. It is supposed to be. The sleeve 21 is made of a synthetic resin 27 from the ring 21 to the inner peripheral portion of the segment 22 so that the claw portion 23 can be elastically pivoted with respect to the ring 21 portion. The end face 24 of the sleeve segment 22 is formed with a brass plate 26 in an uneven shape, and the recess 26a is covered with a synthetic resin 27 to form a stepped portion 27a protruding from the protrusion (contact portion) 26b. The step portion 27 a can receive a strong force from the nut 3. In addition, several protrusions 25 are attached to the outer periphery of the rear end portion of the ring 21 of the sleeve 2 and are held by the nut 3.

The nut 3 is a conductive metal member having an opening through which the corrugated pipe to be connected is passed, and a male screw 31 for screwing into the female screw 17 of the joint body is attached to the outer periphery of one end. A locking portion 7 is provided in the vicinity of the terminal end (left side of the figure) of the male screw 31.
As shown in FIG. 2, the locking portion 7 of the nut 3 is formed with an inclined surface 71 whose diameter is reduced toward the male screw 31 and a locking surface 72 on the opposite side. The outer diameter of the locking portion 7 is larger than the mountain diameter of the male screw 31.

  A claw or an annular protrusion 32 protrudes radially inward from the inner end of the male screw 31 of the nut 3 and is caught by the protrusion 25 attached to the sleeve, so that the sleeve 2 is separated from the nut 3 in the axial direction. To prevent. The claw or the annular projection 32 may be provided by forming an inner circumferential groove at the inner end of the male screw 31. The nut 3 and the sleeve 2 are rotatably attached. When the nut 3 is loosely screwed into the joint body 1 and the sleeve 2 is pushed deeply into the nut 3, the outer periphery of the claw 23 at the tip of the sleeve 2 is held at the position of the annular groove 16. Is done. An end portion of the male screw 31 of the nut is a pressing surface (hereinafter referred to as a flange surface) 33, and when the nut 3 is tightened with respect to the main body 1, the end surface 24 of the sleeve 2 is brought deeper with respect to the joint main body 1. It comes to push.

  With this pipe joint, with the nut 3 loosely screwed into the main body, when the flexible corrugated pipe 4 with several resin covers 41 removed at the tip is inserted into the joint main body 1 from the opening of the nut, the corrugated pipe 4 The tip 2 or the crest 42 of the tip pushes the claw 23 protruding toward the inside in the radial direction of the tip of the sleeve 2, so that the sleeve 2 advances to the innermost position in the through hole 11 with respect to the joint body 1. . An annular concave groove 16 of the joint main body is located on the outer periphery of the tip protrusion of the sleeve that comes to the innermost position. The claw portion 23 at the end of the sleeve is subjected to a force further from the end of the corrugated tube. The segment part 22 at the front part of the sleeve performs an elastic pivoting movement with the integrated ring part 21 at the rear part as a fulcrum, and the claw part 23 at the front end of the sleeve opens and climbs over the peak 42 of the corrugated tube to the first valley 43. The nail part 23 enters. For example, when the distance from the claw 23 at the sleeve tip to the airtight surface of the shoulder inside the main body is a length corresponding to about one mountain of the corrugated tube, the claw 23 of the sleeve is the first trough 43 of the corrugated tube. In this state, the tip of the corrugated tube hits the airtight surface, preventing further insertion.

  A structure in which only one mountain can be inserted is more desirable than a structure in which several mountains can be inserted. In the case of a structure in which several piles can be inserted, it is not known whether one pile is inserted, whether two piles are inserted, or whether it is inserted to the limit after tightening the nut 3 tightly. If only one pile can be inserted, it can be determined whether it is inserted all the way or not. This is because the claw portion 23 of the sleeve cannot be inserted any more in the state where it enters the first valley 43 of the corrugated tube as described above. In this state, once the corrugated tube is pulled out, the claw portion 23 of the sleeve prevents the tube from being pulled out. This confirms that the corrugated tube has been inserted normally. On the contrary, when the corrugated tube is pulled out, it means that the claw portion 23 does not get over the peak 42 of the corrugated tube, and it is possible to know that it is necessary to push the tube further. In addition, about one mountain here means that one mountain can be inserted in the range of 0.5 mountain to 1.5 mountain.

  After the corrugated tube 4 is inserted into the sleeve 2, a force for pulling out the corrugated tube 4 from the sleeve 2 may act on the corrugated tube 4. At this time, the sleeve 2 is pulled in the direction of the nut 3 and slides in the axial direction in a state where the peak 42 of the corrugated tube is caught on the claw portion 23 attached to the sleeve tip. When the end surface 24 of the sleeve hits the flange surface 33 of the nut, the sleeve 2 stops. When the sleeve 2 returns to this position, the outer periphery of the segment portion 22 of the sleeve moves away from the annular concave groove 16 of the main body to the portion where the inner diameter of the main body 1 is narrow or the female screw 17. When the corrugated tube is pulled out at this location, the corrugated tube crest 42 is caught on the inner peripheral end of the claw 23 at the tip of the sleeve, and the segment portion 22 of the sleeve is elastically pivoted using the integral ring portion 21 as a fulcrum. And However, since the inner diameter of the outer peripheral body of the segment portion 22 is narrow and the claw portion 23 at the tip of the sleeve does not expand, the corrugated tube 4 is prevented from coming off.

    After the corrugated tube 4 is inserted into the sleeve 2 of the joint, the nut 3 is turned and the male screw 31 of the nut is tightened along the female screw 17 of the main body. The nut 3 turns lightly until the nut flange surface 33 abuts against the stepped portion 27a which is the end surface 24 of the sleeve segment 22. After the flange surface 33 of the nut hits the end surface 24 of the sleeve, the sleeve 2 is configured to be slidable in the axial direction of the joint body 1 without following the rotation of the nut 3. With the tightening of 3, the sleeve 2 is pushed and advanced toward the back of the through hole 11 of the main body. At this time, since the step portion 27 a of the synthetic resin 27 of the sleeve 2 is formed so as to protrude from the convex portion 26 b of the brass plate 26, the brass plate 26 is in an electrically insulated state without contacting the nut 3. .

The inner surface taper portion 15 is provided at the back of the through-hole portion 11 of the main body, and the inner diameter of the taper surface 15 is reduced as it advances to the back. On the other hand, the claw portion 23 in the inner diameter direction at the tip of the sleeve is in the first or second valley 43 of the corrugated tube 4, so that the valley in which the sleeve claw portion 23 is contained as the sleeve 2 advances to the back. 43 is pressed in the radial direction, and the crest 42 on which the claw portion 23 of the sleeve has climbed is pressed against the airtight surface of the shoulder 14 of the main body with the claw portion 23, and the end portion of the corrugated tube 4 for one crest is crushed and compressed. Full airtightness is obtained (see FIG. 3).
At this time, since the sleeve 2 is pushed into the nut 3 and is prevented from moving by the shoulder portion 14, the step portion 27a of the sleeve 2 is strongly crushed by the flange surface 33 of the nut 3, and the flange surface 33 of the nut 3 and the sleeve The convex portions 26b of the second brass plate 26 come into contact with each other and become electrically conductive.

On the other hand, in the process of turning the nut 3 and tightening the male screw 31 along the female screw 17 of the joint body, the engaging portion 6 of the joint body 1 and the engaging portion 7 of the nut 3 gradually approach each other. The inclined surface 61 of the joint body 1 and the inclined surface 71 of the nut 3 come into contact with each other and move so as to get over the locking portions 6 and 7. At this time, the torque for tightening the nut 3 increases, and the process in which the locking portions 6 and 7 are engaged can be recognized.
And as shown in FIG. 4, when the latching | locking part 7 of the nut 3 passes to the back | inner side (right side of a figure) of the 1 coupling main body stop part 6, it will recognize that the tightening torque became light and construction was completed. be able to.

  If a force that loosens the nut 3 is applied after the construction is completed, the engagement surfaces 62 and 72 of the joint body 1 and the nut 3 come into contact with each other, and no further loosening occurs. Therefore, highly reliable airtightness and retaining property can be maintained.

  That is, in the process of tightening the nut 3 to the joint body 1, the nut 3 and the sleeve 2 are in an electrically insulated state, and when the nut 3 is tightened to the joint body 1, the nut 3 and the sleeve 2 are electrically connected. It becomes. And since the corrugated pipe | tube 4 and the sleeve 2 are electrical continuity in the nail | claw part 23, the corrugated pipe | tube 4 and the coupling main body 1 will be in an electrical continuity state. Since the corrugated pipe joint is also connected to the other end of the corrugated pipe 4, the construction manager can confirm that the electrical continuity between the corrugated pipe joints is confirmed using an electric tester or the like. Can be inspected.

  The height at which the step portion 27a of the synthetic resin 27 of the sleeve 2 protrudes from the convex portion 26b of the brass plate 26 may be such that electrical insulation is maintained during the tightening process of the nut 3, and is 0.1 to 0. About 6 mm is preferable. The sleeve 2 and the inner tapered surface 15 of the joint body 1 can be electrically insulated.

<Second form>
In the second embodiment, the form of the sleeve is different from that of the first embodiment. FIG. 6 shows a sleeve used in the second embodiment. Hereinafter, detailed description of the same configuration as that of the first embodiment will be omitted.

  The sleeve 2A shown in FIG. 6 is inserted into the through hole 11 of the joint body 1 and accommodates and holds the free end of the flexible corrugated tube 4. The sleeve 2A has an integrated ring 21 at the rear part, and the front part is divided into a segment 22 by an axial slit. The sleeve 2A faces the shoulder part 14 in the through hole 11 of the joint body 1 at the tip of the segment. The claw portion 23 protrudes from the portion toward the inside in the radial direction. A circle d formed by the tip of the claw portion 23 is smaller than the diameter of the peak of the corrugated tube to be inserted and larger than the diameter of the valley.

  In FIG. 6, the hatched portion of the broken line is the outer peripheral portion of the claw portion 23 and the segment 22, which is composed of an integral brass plate 26 to increase rigidity, and the outer peripheral portion of the claw portion 23 and the segment 22 is electrically connected. It is supposed to be. The sleeve 21 is made of a synthetic resin 27 from the ring 21 to the inner peripheral portion of the segment 22 so that the claw portion 23 can be elastically pivoted with respect to the ring 21 portion. A portion of the brass plate 26 is exposed on the back side of the claw portion 23 of the segment 22 of the sleeve 2A and is opposed to the inner tapered surface 15 of the joint body 1, and part of the synthetic resin 27 is brass. A protruding portion 28 protruding from the plate 26 is formed. In addition, several protrusions 25 are attached to the outer periphery of the rear end portion of the ring 21 of the sleeve 2 </ b> A and are held by the nut 3.

  After the corrugated tube 4 is inserted into the sleeve 2 of the joint, the nut 3 is turned and the male screw 31 of the nut is tightened along the female screw 17 of the main body. The nut 3 turns lightly until the flange surface 33 of the nut hits the end surface 24 of the sleeve. After the nut flange surface 33 abuts against the end face 24 of the sleeve, the sleeve 2 is rotatable with respect to the rotation of the nut 3, so that the tube is not twisted and the sleeve 2 is tightened with the nut 3 without being twisted. It is pushed toward the back of the through-hole portion 11 and proceeds. At this time, the protruding portion 28 of the synthetic resin 27 of the sleeve 2 </ b> A is formed so as to protrude from the brass plate 26, so that the brass plate 26 is in an electrically insulated state without contacting the joint body 1.

The inner surface taper portion 15 is provided at the back of the through-hole portion 11 of the main body, and the inner diameter of the taper surface 15 is reduced as it advances to the back. On the other hand, the claw portion 23 in the inner diameter direction at the tip of the sleeve is in the first or second valley 43 of the corrugated tube 4, so that the valley in which the sleeve claw portion 23 is contained as the sleeve 2 advances to the back. 43 is tightened in the radial direction, and the mountain 42 on which the claw portion 23 of the sleeve has overcome is pressed against the airtight surface of the shoulder portion 14 of the main body with the claw portion 23 and compressed to obtain complete airtightness.
At this time, the sleeve 2 is pushed into the nut 3, and the outer periphery of the sleeve 2 </ b> A is squeezed by the inner tapered surface 15, so that the protruding portion 28 of the sleeve 2 </ b> A is strongly crushed by the inner tapered surface 15. The inner tapered surface 15 and the brass plate 26 of the sleeve 2A come into contact with each other and become electrically conductive.

  That is, in the process of tightening the nut 3 to the joint body 1, the joint body 1 and the sleeve 2 </ b> A are in an electrically insulated state, and when the tightening of the nut 3 to the joint body 1 is completed, the joint body 1 and the sleeve 2 are electrically connected. Continuity. And since the corrugated pipe | tube 4 and the sleeve 2 are electrical continuity in the nail | claw part 23, the corrugated pipe | tube 4 and the coupling main body 1 will be in an electrical continuity state. Since the corrugated pipe joint is also connected to the other end of the corrugated pipe 4, the construction manager can confirm that the electrical continuity between the corrugated pipe joints is confirmed using an electric tester or the like. Can be inspected.

  The height at which the protruding portion 28 of the synthetic resin 27 of the sleeve 2A protrudes from the brass plate 26 is such that electrical insulation is maintained in the tightening process of the nut 3, and is about 0.1 to 0.6 mm. preferable. The sleeve 2A and the nut 3 can be electrically insulated.

  Further, the brass plate 26 on the end surface 24 of the sleeve segment 22 is formed in a concavo-convex shape, and the concave portion 26a is covered with a synthetic resin 27 to form a stepped portion 27a protruding from the convex portion (contact portion) 26b. In addition, the brass plate 26 is partially exposed on the back side of the claw portion 23 of the segment 22 and facing the inner tapered surface 15 of the joint body 1, and a part of the synthetic resin 27 is part of the brass plate 26. The protruding portion 28 can also be formed. In this case, in the process of tightening the nut 3 to the joint body 1, the joint body 1 and the nut 3 and the sleeve 2A are in an electrically insulated state, and when the nut 3 is tightened to the joint body 1, the joint body 1 and The nut 3 and the sleeve 2 are electrically connected. And since the corrugated pipe | tube 4 and the sleeve 2 are electrical continuity in the nail | claw part 23, the corrugated pipe | tube 4 and the coupling main body 1 will be in an electrical continuity state.

  Regarding the locking of the joint body 1 and the nut 3 in this embodiment, the locking part 6 is provided on the starting point side (left side in the figure) of the female thread 17 of the joint body 1 and the locking part 7 is provided on the terminal side of the male screw 31 of the nut 3. Although provided, the engaging part 6 can be provided on the terminal end side (right side in the drawing) of the female thread 17 of the joint body 1 and the engaging part 7 can be provided on the male screw 31 starting point side of the nut 3. In this case, the inner diameter of the locking portion 6 may be set smaller than the mountain diameter of the female screw 17, and the outer diameter of the locking portion 7 may be set smaller than the valley diameter of the male screw 31.

  As shown in the figure, the gasket 12 can be inserted into the shoulder portion of the main body to improve the airtight performance. Furthermore, a rubber packing 13 containing expanded graphite can be put on the outer peripheral side of the gasket 12 to improve safety in the event of a fire.

  When the corrugated tube 4 is not sufficiently inserted into the sleeve 2 of the joint and the nut 3 is tightened to the main body 1, the sleeve 2 is tightened to the back along the tapered surface 15. Therefore, even after the nut 3 is tightened, the corrugated tube 4 easily comes out of the joint body 1 and it can be seen that the connection is not correct.

  In the joint of the present invention, with the nut 3 loosely attached to the main body 1 in advance, the annular protrusion 32 at the tip of the nut 3 and the protrusion 25 at the rear end of the sleeve are caught to determine the position of the sleeve. Since the tip of the sleeve with the directional claw 23 must be placed on the annular groove 16 facing the inner surface of the main body, the main body 1 of the nut 3 with the nut 3 loosely attached. It is important that the screw 31 of the nut 3 is fastened to the position of the screw 17 of the main body.

  Therefore, in order to determine the position of the nut 3, it is preferable to insert the spacer ring 5 between the nut end surface and the main body end surface and fasten the nut 3 to the main body 1. When the sleeve 2 is fully inserted in this state, the back of the tip of the sleeve 2 comes to the position of the annular groove 16 of the main body, and the distance between the front of the sleeve and the shoulder airtight surface of the main body is the corrugated. It corresponds to the length of about one or two peaks of the tube. The spacer ring 5 is made of an elastic plastic or the like, and has a substantially C-shape with a notch in the axial direction at a part of the circumference.

  In a state where the nut is weakly tightened to the main body, the spacer ring 5 is sandwiched between the nut and the end surface of the main body, so that the position of the nut can be obtained. However, when the nut is strongly tightened, the spacer ring 5 is broken at the notch and is detached from between the end surface of the nut and the main body and attached to the outer periphery of the main body. In addition, after inserting the corrugated tube, the spacer ring 5 between the nut and the end face of the main body can be removed by hand. In this way, the nut can be tightened.

  The corrugated tube 4 is often provided with a resin cover 41 such as vinyl chloride in order to improve weather resistance and prevent external damage. In that case, the cover of the length of 4-5 ridges is removed from the end of the corrugated tube, and the connection is inserted into the joint of the present invention. An O-ring 36 is attached to the outside of the threaded portion between the nut 3 of the joint and the main body 1, and an E-shaped packing 37 is attached to the opposing portion of the nut 3 and the resin cover 41 of the corrugated pipe. These seals can prevent moisture from entering the inside of the joint.

1: Joint body 2, 2A: Sleeve 3: Nut, 4: Corrugated pipe 5: Spacer ring, 11: Through hole 12: Heat resistant gasket, 13: Rubber packing with expanded graphite 14: Shoulder portion, 15: Tapered inner surface 16 : Annular groove, 17: female thread 18: notch, 19: male thread 21: ring, 22: segment 23: claw part of sleeve 2, 24: end face of segment 25: protrusion, 26: brass plate, 26a: Concave part, 26b: convex part (contact part)
27: Resin, 27a: Stepped portion, 28: Protruding portion of sleeve 2, 31: Male screw 32: Projection of nut 3 (pressing surface), 33: Flange surface (pressing surface)
36: O-ring, 37: E-shaped packing 41: Resin cover of corrugated pipe 4, 42: Corrugated pipe crest 43: Corrugated pipe trough 6: Locking portion of joint body 1, 61: Inclined surface, 62: Locking Surface 7: Locking portion of nut 3, 71: Inclined surface, 72: Locking surface

Claims (5)

A joint body having a through hole, a sleeve for holding the end of the corrugated pipe inside the through hole, and a nut screwed into a screw of the joint body,
The joint body has a shoulder portion having an airtight surface therein, and an inner surface of the through hole is formed with a tapered inner surface that fits one end of the sleeve adjacent to the shoulder portion,
The shoulder is provided with a gasket that seals the end of the corrugated tube,
Until the screwing of the nut into the joint body is completed, the sleeve interrupts the electrical continuity between the sleeve and the joint body or the sleeve and the nut, thereby blocking the corrugated tube and the sleeve. After the electrical continuity with the joint main body is cut off and the screwing of the nut into the joint main body is completed, the electrical continuity between the sleeve and the joint main body or the electrical continuity between the sleeve and the nut is the nut. An electrical connection between the corrugated pipe and the joint body is restored by recovery by the screwing action of the pipe joint. A joint body having a through hole, a sleeve for holding the end of the corrugated pipe inside the through hole, and a nut screwed into a screw of the joint body,
The joint body has a shoulder portion having an airtight surface therein, and an inner surface of the through hole is formed with a tapered inner surface that fits one end of the sleeve adjacent to the shoulder portion,
The shoulder is provided with a gasket that seals the end of the corrugated tube,
The sleeve has a claw projecting toward the radially inner diameter side at one end, and when the nut is screwed into the joint body, the abutting portion that abuts the pressing surface formed on the nut is disposed at the other end. A plurality of metal segments having a ring-shaped synthetic resin substrate formed integrally with these metal segments,
The synthetic resin base has a stepped portion that protrudes at least from the contact portion of the metal segment toward the nut and contacts a pressing surface formed on the nut,
A pipe joint characterized in that the sleeve and the joint body are electrically insulated. A joint body having a through hole, a sleeve for holding the end of the corrugated pipe in the through hole, and a nut screwed into a screw of the joint body,
The joint body has a shoulder portion with an airtight surface inside, and a tapered inner surface is formed on the inner surface of the through-hole so as to fit one end of the sleeve adjacent to the shoulder portion,
The shoulder is provided with a gasket that seals the end of the corrugated tube,
The sleeve is composed of a plurality of metal segments having a claw portion projecting toward the radially inner diameter side at one end, and a ring-shaped synthetic resin base body integrally molded with the metal segments,
The tapered surface side of the joint body in the sleeve forms a protruding portion from which a part of the synthetic resin substrate protrudes in a state where the metal segment is exposed,
A pipe joint characterized in that the sleeve and the nut are electrically insulated. A joint body having a through hole, a sleeve for holding the end of the corrugated pipe in the through hole, and a nut screwed into a screw of the joint body,
The joint body has a shoulder portion with an airtight surface inside, and a tapered inner surface is formed on the inner surface of the through-hole so as to fit one end of the sleeve adjacent to the shoulder portion,
The shoulder is provided with a gasket that seals the end of the corrugated tube,
The sleeve has a claw projecting toward the radially inner diameter side at one end, and when the nut is screwed into the joint body, the abutting portion that abuts the pressing surface formed on the nut is disposed at the other end. A plurality of metal segments having a ring-shaped synthetic resin substrate formed integrally with these metal segments,
The synthetic resin base has a stepped portion that protrudes at least from the abutting portion of the metal segment toward the nut and abuts against a pressing surface formed on the nut,
The pipe joint according to claim 1, wherein the tapered surface side of the joint main body of the sleeve is formed with a protruding portion from which a part of the synthetic resin substrate protrudes with the metal segment exposed.   A locking portion is provided in the vicinity of the screw of the joint body, and a locking portion is formed in the vicinity of the screw of the nut, and when the screwing of the joint body and the nut is finished, the locking portion of the nut and the coupling body are locked. The pipe joint according to any one of claims 1 to 4, wherein the portion is fitted and locked.

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